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Veterinary Immunology and... Feb 2024Bovines infected by bovine leukemia virus (BLV) are characterized by presenting low proviral load (LPL) or high proviral load (HPL). It is reported that animals with HPL...
Altered apoptosis and proliferation in milk cells and PBMc from BLV-infected bovines with different proviral loads: Possible role of the BCL-2 family proteins, TNF-alpha, and receptors.
Bovines infected by bovine leukemia virus (BLV) are characterized by presenting low proviral load (LPL) or high proviral load (HPL). It is reported that animals with HPL in peripheral blood mononuclear cells (PBMCs) present a decrease in apoptosis, an increase in viability and the proliferation rate, while animals that maintain an LPL have an intrinsic ability to control the infection, presenting an increased apoptosis rate of their PBMCs. However, there is little information on the effect of BLV on these mechanisms when the virus infects somatic milk cells (SC). This study investigates the mechanisms underlying apoptosis in milk and blood from BLV-infected animals with HPL and LPL. Relative levels of mRNA of tumor necrosis factor-α (TNF-α), TNF receptor 1 (TNF-RI), TNF receptor 2 (TNF-RII), anti-apoptotic B-cell lymphoma 2 protein (Bcl-2), and pro-apoptotic Bcl-2-like protein 4 (Bax) were measured in SC and PBMCs using quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay. A significant decrease in the expression of TNF-α in SC from HPL animals vs non-infected bovines was observed, but the infection in SC with BLV did not show a modulation on the expression of TNF receptors. A significant increase in TNF-RI expression in PBMCs from HPL bovines compared to LPL bovines was observed. No significant differences in PBMCs between HPL and LPL compared to non-infected animals concerning TNF-α, TNF-RI, and TNF-RII expression were found. There was a significant increase of both Bcl-2 and Bax in SC from LPL compared to non-infected bovines, but the Bcl-2/Bax ratio showed an anti-apoptotic profile in LPL and HPL bovines compared to non-infected ones. Reduced mRNA expression levels of Bax were determined in the PBMCs from HPL compared to LPL subjects. In contrast, BLV-infected bovines did not differ significantly in the mRNA expression of Bax compared to non-infected bovines. Our data suggest that the increased mRNA expression of Bax corresponds to the late lactation state of bovine evaluated and the exacerbated increase of mRNA expression of Bcl-2 may be one of the mechanisms for the negative apoptosis regulation in the mammary gland induced by BLV infection. These results provide new insights into the mechanism of mammary cell death in HPL and LPL BLV-infected bovine mammary gland cells during lactation.
Topics: Animals; Cattle; Female; Apoptosis; bcl-2-Associated X Protein; Cattle Diseases; Cell Proliferation; Enzootic Bovine Leukosis; Leukemia Virus, Bovine; Leukocytes, Mononuclear; Milk; Proviruses; Receptors, Tumor Necrosis Factor, Type II; RNA, Messenger; Tumor Necrosis Factor-alpha
PubMed: 38154260
DOI: 10.1016/j.vetimm.2023.110703 -
Frontiers in Immunology 2023HTLV-1 infection is a neglected disease, despite estimates of 10 million people infected worldwide and producing life-threatening illnesses in 10% of carriers. Sexual...
BACKGROUND
HTLV-1 infection is a neglected disease, despite estimates of 10 million people infected worldwide and producing life-threatening illnesses in 10% of carriers. Sexual transmission is the main route of contagion. However, HTLV-1 is not listed among sexually transmitted infections (STIs).
METHODS
Serum from all consecutive individuals who had attended six STI clinics across Spain during the last 12 months were tested for HTLV antibodies using a commercial enzyme immunoassay (EIA). Reactive samples were confirmed by immunoblot.
RESULTS
A total of 2,524 samples were examined. The majority (1,936; 76.7%) belonged to men, of whom 676 (34.9%) were men who have sex with men (MSM) receiving HIV pre-exposure prophylaxis. Although native Spaniards predominated (1,470; 58.2%), up to 593 (23.5%) came from Latin America and 139 (5.5%) were African. A total of 26 individuals were initially EIA reactive and immunoblot confirmed 5 as HTLV-1 and 7 as HTLV-2. All but one HTLV-1+ case came from Latin America. Three were men and two were women. Among Latin Americans, the HTLV-1 seroprevalence was 0.67%. In contrast, all seven HTLV-2+ were native Spaniards and former injection drug users, and all but one were HIV+.
CONCLUSION
The rate of HTLV infection among individuals with STIs in Spain is 0.5%, which is greater than in the general population. These results support the introduction of universal HTLV screening in persons who attend clinics for STIs.
Topics: Male; Humans; Female; Homosexuality, Male; Spain; Seroepidemiologic Studies; Sexual and Gender Minorities; Deltaretrovirus Infections; Human T-lymphotropic virus 1; Sexually Transmitted Diseases; HIV Infections
PubMed: 38143748
DOI: 10.3389/fimmu.2023.1277793 -
The Journal of Veterinary Medical... Feb 2024Enzootic bovine leukosis (EBL) is B-cell lymphoma in cattle caused by bovine leukemia virus (BLV) infection. The incidence of EBL has been increasing since 1998 in...
Enzootic bovine leukosis (EBL) is B-cell lymphoma in cattle caused by bovine leukemia virus (BLV) infection. The incidence of EBL has been increasing since 1998 in Japan, resulting in significant economic losses for farms. The BLV genome integrates with the host genome as provirus, leading to sustainably infection. Although most of the BLV-infected cattle are aleukemic, some cattle cause persistent lymphocytosis (PL) and subsequently develop EBL. Recent reports suggest the association between the risk for the transmission of BLV and the developing EBL and the proviral load (PVL) in BLV-infected cattle, which cannot measure readily in the field. This study aims to build a statistical model for predicting PVL of BLV-infected asymptomatic or PL cattle based on data accessible in the field. Five negative binomial regression models with different linear predictors were built and compared for the predictability of PVL. Consequently, the model with two explanatory variables (age in months and logarithm of lymphocyte count) was selected as the best model. The model can be used in the field as a cost-beneficial supporting tool to estimate the risk of transmission of BLV and developing EBL in infected cattle.
Topics: Cattle; Animals; Leukemia Virus, Bovine; Proviruses; Enzootic Bovine Leukosis; Lymphocyte Count; Models, Statistical; Cattle Diseases
PubMed: 38123328
DOI: 10.1292/jvms.23-0157 -
Virology Journal Dec 2023Human T-lymphotropic virus 1 (HTLV-1) is associated with the development of several pathologies and chronic infection in humans. The inefficiency of the available...
BACKGROUND
Human T-lymphotropic virus 1 (HTLV-1) is associated with the development of several pathologies and chronic infection in humans. The inefficiency of the available treatments and the challenge in developing a protective vaccine highlight the need to produce effective immunotherapeutic tools. The HTLV-1 basic leucine zipper (bZIP) factor (HBZ) plays an important role in the HTLV-1 persistence, conferring a survival advantage to infected cells by reducing the HTLV-1 proteins expression, allowing infected cells to evade immune surveillance, and enhancing cell proliferation leading to increased proviral load.
METHODS
We have generated a recombinant Modified Virus Vaccinia Ankara (MVA-HBZ) and a plasmid DNA (pcDNA3.1(+)-HBZ) expressing a multiepitope protein based on peptides of HBZ to study the immunogenic potential of this viral-derived protein in BALB/c mice model. Mice were immunized in a prime-boost heterologous protocol and their splenocytes (T CD4 and T CD8) were immunophenotyped by flow cytometry and the humoral response was evaluated by ELISA using HBZ protein produced in prokaryotic vector as antigen.
RESULTS
T CD4 and T CD8 lymphocytes cells stimulated by HBZ-peptides (HBZ and HBZ) showed polyfunctional double positive responses for TNF-α/IFN-γ, and TNF-α/IL-2. Moreover, T CD8 cells presented a tendency in the activation of effector memory cells producing granzyme B (CD44/CD62L), and the activation of Cytotoxic T Lymphocytes (CTLs) and cytotoxic responses in immunized mice were inferred through the production of granzyme B by effector memory T cells and the expression of CD107a by CD8 T cells. The overall data is consistent with a directive and effector recall response, which may be able to operate actively in the elimination of HTLV-1-infected cells and, consequently, in the reduction of the proviral load. Sera from immunized mice, differently from those of control animals, showed IgG-anti-HBZ production by ELISA.
CONCLUSIONS
Our results highlight the potential of the HBZ multiepitope protein expressed from plasmid DNA and a poxviral vector as candidates for therapeutic vaccine.
Topics: Mice; Humans; Animals; Human T-lymphotropic virus 1; CD8-Positive T-Lymphocytes; Granzymes; Tumor Necrosis Factor-alpha; Vaccines, DNA; Viral Proteins; Vaccinia virus; DNA; Basic-Leucine Zipper Transcription Factors; Retroviridae Proteins
PubMed: 38115107
DOI: 10.1186/s12985-023-02264-z -
Scientific Reports Dec 2023Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leucosis (EBL), which has been reported worldwide. The expression of viral structural proteins:...
Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leucosis (EBL), which has been reported worldwide. The expression of viral structural proteins: surface glycoprotein (gp51) and three core proteins - p15 (matrix), p24 (capsid), and p12 (nucleocapsid) induce a strong humoral and cellular immune response at first step of infection. CD4+ T-cell activation is generally induced by bovine leukocyte antigen (BoLA) region- positive antigen-presenting cells (APC) after processing of an exogenous viral antigen. Limited data are available on the BLV epitopes from the core proteins recognized by CD4+ T-cells. Thus, immunoinformatic analysis of Gag sequences obtained from 125 BLV isolates from Poland, Canada, Pakistan, Kazakhstan, Moldova and United States was performed to identify the presence of BoLA-DRB3 restricted CD4+ T-cell epitopes. The 379 15-mer overlapping peptides spanning the entire Gag sequence were run in BoLA-DRB3 allele-binding regions using a BoLA-DRB- peptide binding affinity prediction algorithm. The analysis identified 22 CD4+ T-cell peptide epitopes of variable length ranging from 17 to 22 amino acids. The predicted epitopes interacted with 73 different BoLA-DRB3 alleles found in BLV-infected cattle. Importantly, two epitopes were found to be linked with high proviral load in PBMC. A majority of dominant and subdominant epitopes showed high conservation across different viral strains, and therefore could be attractive targets for vaccine development.
Topics: Animals; Cattle; CD4-Positive T-Lymphocytes; Epitopes, T-Lymphocyte; Leukemia Virus, Bovine; Gene Products, gag; Leukocytes, Mononuclear; HLA-DR Antigens; Peptides
PubMed: 38102157
DOI: 10.1038/s41598-023-48899-4 -
Veterinarni Medicina Oct 2023Enzootic bovine leucosis is caused by bovine leukaemia virus (BLV), a belonging to the family . BLV causes huge economic losses to the dairy industry in the form...
Enzootic bovine leucosis is caused by bovine leukaemia virus (BLV), a belonging to the family . BLV causes huge economic losses to the dairy industry in the form of decreased milk production, premature culling, and poor reproductive performance of the animals. The aim of the present study was to determine the seroprevalence of BLV infection in buffalo in two districts of Punjab, Pakistan. A total of 384 samples were collected and analysed using a commercial indirect enzyme-linked immunosorbent assay (ELISA) to investigate the seroprevalence of BLV through the detection of the anti-BLV gp51 antibody. A predesigned data questionnaire proforma was employed to find out the association of risk factors with disease. Overall, 18.2% of buffaloes were seropositive for BLV in the study population. The results revealed a significant association ( < 0.05) of age with BLV infection. Furthermore, milk yield and pregnancy had a significant association with the seroprevalence of BLV infection in buffalo whereas no significant association was found with sex, breeding, and health status. Biochemical and oxidative stress markers revealed a significant decrease in liver enzymes alanine transaminase (ALT) and aspartate transaminase (AST), glutathione peroxidase (GPX), and superoxide dismutase (SOD) in seropositive animals as compared to healthy animals. It is concluded that BLV has a considerable prevalence in buffalo in Punjab, Pakistan and there is a dire need to investigate the disease epidemiology at both national and international levels and strategies should be developed to implement an effective control program.
PubMed: 38028205
DOI: 10.17221/57/2023-VETMED -
International Journal of Molecular... Nov 2023Human T-cell tropic virus type 1 (HTLV-1) is known to be mainly transmitted by cell-to-cell contact due to the lower infectivity of the cell-free virion. However, the...
Human T-cell tropic virus type 1 (HTLV-1) is known to be mainly transmitted by cell-to-cell contact due to the lower infectivity of the cell-free virion. However, the reasons why cell-free HTLV-1 infection is poor remain unknown. In this study, we found that the retrovirus pseudotyped with HTLV-1 viral envelope glycoprotein (Env) was infectious when human immunodeficiency virus type 1 (HIV-1) was used to produce the virus. We found that the incorporation of HTLV-1 Env into virus-like particles (VLPs) was low when HTLV-1 Gag was used to produce VLPs, whereas VLPs produced using HIV-1 Gag efficiently incorporated HTLV-1 Env. The production of VLPs using Gag chimeras between HTLV-1 and HIV-1 Gag and deletion mutants of HIV-1 Gag showed that the p6 domain of HIV-1 Gag was responsible for the efficient incorporation of HTLV-1 Env into the VLPs. Further mutagenic analyses of the p6 domain of HIV-1 Gag revealed that the PTAP motif in the p6 domain of HIV-1 Gag facilitates the incorporation of HTLV-1 Env into VLPs. Since the PTAP motif is known to interact with tumor susceptibility gene 101 (TSG101) during the budding process, we evaluated the effect of TSG101 knockdown on the incorporation of HTLV-1 Env into VLPs. We found that TSG101 knockdown suppressed the incorporation of HTLV-1 Env into VLPs and decreased the infectivity of cell-free HIV-1 pseudotyped with HTLV-1 Env. Our results suggest that the interaction of TSG101 with the PTAP motif of the retroviral L domain is involved not only in the budding process but also in the efficient incorporation of HTLV-1 Env into the cell-free virus.
Topics: Humans; Amino Acid Motifs; Gene Products, gag; Human T-lymphotropic virus 1; Virion; HIV-1; Gene Products, env
PubMed: 38003710
DOI: 10.3390/ijms242216520 -
Journal of Clinical Virology : the... Dec 2023HTLV-1 infection is a neglected disease. Over 10 million people are infected worldwide, with hot spots of high endemicity across all continents. Roughly 5% of HTLV-1...
BACKGROUND
HTLV-1 infection is a neglected disease. Over 10 million people are infected worldwide, with hot spots of high endemicity across all continents. Roughly 5% of HTLV-1 carriers develop HTLV-1-associated myelopathy (HAM), a progressive subacute neurological disabling disease.
METHODS
We report the main features of patients diagnosed with HAM up to date in Spain, a non-endemic country with a relatively high migrant flow from Latin America and Equatorial Africa, where HTLV-1 is endemic.
RESULTS
A total of 451 cases of HTLV-1 had been recorded in Spain until the end of year 2022. HAM had been diagnosed in 58 (12.9%). The current incidence is of 2-3 new cases per year. Women represent 76%. Mean age at diagnosis is 49 years-old. Nearly 60% are Latin Americans. Although sexual transmission is the most likely route of HTLV-1 acquisition, up to 6 individuals had been infected following solid organ transplantation. Rapid onset myelopathy developed in all but one of these transplant recipients from three HTLV-1-positive donors. HTLV-1 subtype 1a transcontinental was the only variant recognized in HAM patients. HTLV-1 proviral load was significantly greater in HAM patients than in asymptomatic HTLV-1 carriers (677 vs 104 HTLV-1 DNA copies/10 PBMC; p = 0.012). Symptom relief medications and physiotherapy have been the only treatment providing some benefit to HAM patients. Neither significant clinical nor virological efficacy was noticed using antiretrovirals in at least 9 HAM patients. Two thirds of HAM patients ended up in a wheelchair and with urinary/fecal sphincter incontinence.
CONCLUSION
HAM is the most frequent clinical manifestation of HTLV-1 infection in Spain, a non-endemic country. Middle aged women migrants from Latin America are the most frequently affected. Two thirds end up in a wheelchair despite using antiretroviral therapy.
Topics: Middle Aged; Humans; Female; Paraparesis, Tropical Spastic; Spain; Leukocytes, Mononuclear; HTLV-I Infections; Human T-lymphotropic virus 1; Viral Load
PubMed: 38000189
DOI: 10.1016/j.jcv.2023.105619 -
Veterinaria Italiana Mar 2023The retrovirus bovine leukemia virus (BLV) might produce abnormal immune function, associated with susceptibility to developing other infectious diseases, including...
Study of the proviral load levels and mRNA expression of cytokines in peripheral blood mononuclear cells and somatic milk cells in cattle with different BLV infection profiles.
The retrovirus bovine leukemia virus (BLV) might produce abnormal immune function, associated with susceptibility to developing other infectious diseases, including mastitis. This study aimed to determine the proviral load and cytokines gene expression in peripheral blood mononuclear cells (PMBC) and milk somatic cells (SC) in BLV-infected and non-infected cattle. Of 27 BLV-infected cows in PBMC, 17 (62.96%) had a high proviral load (HPL), and 10 (37.04%) had a low proviral load (LPL). All SC samples had low proviral load (LPL-SC). Higher IFN-γ and IL-10 expression, and lower IL-12 and IL-6 expression, were found in PBMC from BLV-infected compared to BLV non-infected cattle. Moreover, higher IFN-γ, IL-12, and IL-6 expression, and lower IL-10 expression were observed in cattle with LPL-PBMC compared to HPL-PBMC. In milk samples, lower IFN-γ and higher IL-12 mRNA expression were observed in LPL-SC compared to BLV non-infected cattle in SC. IL-10 and IL-6 expression mRNA was significantly lower in LPL-SC than in SC from BLV non-infected cattle. This study shows that milk SC maintains lower proviral load levels than PBMC. This first report on Th1 and Th2 cytokines expression levels in SC may be relevant to future control strategies for BLV infection, mastitis, and udder health management.
Topics: Female; Cattle; Animals; Cytokines; Leukocytes, Mononuclear; Interleukin-10; Leukemia Virus, Bovine; Enzootic Bovine Leukosis; Proviruses; Milk; Interleukin-6; Interleukin-12; RNA, Messenger; Mastitis; Cattle Diseases
PubMed: 37994640
DOI: 10.12834/VetIt.2718.20143.3 -
Microbiology Spectrum Dec 2023The World Health Organization estimated that 5-10 million people are infected with human T-cell leukemia virus type 1 (HTLV-1). This number is likely to be...
The World Health Organization estimated that 5-10 million people are infected with human T-cell leukemia virus type 1 (HTLV-1). This number is likely to be underestimated because reliable endemic data are available for only approximately 1.5 billion people worldwide. The point-of-care test is a powerful tool for the easy and quick detection of infections without the requirement for expensive instruments and laboratory equipment. Espline HTLV-I/II, a newly developed rapid immunochromatographic antibody test that was evaluated in this study, might significantly advance our understanding of the global epidemiology of HTLV-1 infection.
Topics: Humans; Human T-lymphotropic virus 1; HTLV-I Infections
PubMed: 37966220
DOI: 10.1128/spectrum.02078-23